+ /* video and audio content can modify its position */
+
+ if (video) {
+ video->modify_position (film, p);
+ }
+
+ /* Only allow the audio to modify if we have no video;
+ sometimes p can't be on an integer video AND audio frame,
+ and in these cases we want the video constraint to be
+ satisfied since (I think) the audio code is better able to
+ cope.
+ */
+ if (!video && audio) {
+ audio->modify_position (film, p);
+ }
+
+ ChangeSignaller<Content> cc (this, ContentProperty::POSITION);
+